I think its pretty obvious that Batman will get his hands on Kryptonite and then it will be an unfair fight for Superman.

If they wanted to exclude Kryptonite, then Batman has absolutely no chance of winning. Superman would throw him into space and Batman would end up halfway across the universe before he even gets killed.

Even with Kryptonite, Superman could fly into Batman so fast he'd scatter like dust before the Kryptonite even took effect. It's a silly debate.